1. Field of the Invention
The present invention generally relates to magnetic recording and reproduction apparatuses, and more particularly to a magnetic recording and reproduction apparatus including a tape loading mechanism.
2. Description of the Related Art
FIG. 1 is an exploded view of a tape loading mechanism 10 of a conventional magnetic recording and reproduction apparatus. The tape loading mechanism 10 includes a driving ring gear member 11, an L ring gear member 20 having a tape guide pole 21, an R ring gear member 30 having a tape guide pole 31, and a gear mechanism 40. The driving ring gear member 11, the L ring gear member 20, and the R ring gear member 30 are superimposed and supported so as to be rotatable independent of one another. Referring to FIGS. 2A through 2C, the gear mechanism 40 includes a gear member 41 that engages the driving ring gear member 11 shown in FIG. 1, a first gear member 50 that engages the gear member 41, and a second gear member 60 that engages the first gear member 50. The first gear member 50 engages the L ring gear member 20, and the second gear member 60 engages the R ring gear member 30.
When the driving ring .gear member 11 is rotated counterclockwise by a motor, the gear member 41 is rotated. The rotation of the gear member 41 is transmitted to the first gear member 50 and further to the second gear member 60. The rotation of the first gear member 50 is transmitted to the L ring gear member 20, so that the L ring gear member 20, together with the tape guide pole 21, is rotated clockwise. The rotation of the second gear member 60 is transmitted to the R ring gear member 30, so that the R ring gear member, together with the tape guide pole 31, is rotated counterclockwise. As a result, a magnetic tape is pulled out to be wound around a rotary drum, thereby terminating tape loading.
While the driving ring gear member 11 is rotated a predetermined angle, the rotation is transmitted to the gear member 41, so that the gear member 41 is rotated. When the driving ring gear member 11 is rotated more than the predetermined angle, the rotation is prevented from being transmitted, so that the gear member 41 remains in a stationary state. While the gear member 41 is rotated a predetermined angle, the rotation is transmitted to the first gear member 50, so that the first gear member 50 is rotated. When the gear member 41 is rotated more than the predetermined angle, the rotation is prevented from being transmitted, so that the first gear member 50 remains in a stationary state. The first and second gear members 50 and 60 are always engaged.
As shown in FIGS. 2A through 2C, the gear member 41 has a cam part 41a disposed on a gear part 41b. The first gear member 50 has a convex cam part 51a formed to project upward (as viewed in FIG. 2B) from a gear tooth 51b−1 of a gear part 51b. The gear part 41b engages the gear part 51b, and the cam part 41a and the cam part 51a are positioned at the same level.
When tape loading is terminated, the gear mechanism 40 enters the state shown in FIG. 3A. In this state, as shown enlarged in FIG. 3B, the cam part 41a of the gear member 41 comes into contact with the convex cam part 51a of the first gear member 50. A spring member (not shown in the drawings) exerts a turning force in the A1 direction on the gear member 41 with the cam part 51a being pressed against the cam part 41a with a force f1.